#include"mystdio.h"
#include<string.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<stdlib.h>
#include<unistd.h>
#include<stdio.h>

mFILE* mfopen(const char* filename, const char* mode)
{
	int fd = -1;
	if(strcmp(mode, "w") == 0)
	{
		fd = open(filename, O_CREAT|O_WRONLY|O_TRUNC, 0666);
	}
	else if(strcmp(mode, "r") == 0)
	{	
		fd = open(filename, O_RDONLY, 0666);
	}
	else if(strcmp(mode, "a") == 0)
	{	
		fd = open(filename, O_CREAT|O_WRONLY|O_APPEND, 0666);
	}
	if(fd < 0) return NULL;
	mFILE* mf = (mFILE*)malloc(sizeof(mFILE));
	if(!mf)
	{
		close(fd);
		return NULL;
	}
	mf->fileno = fd;
	mf->flag = FLUSH_LINE;
	mf->size = 0;
	mf->cap = mf->size;
	return mf;
}

void mfflush(mFILE* stream)
{
	if(stream->size > 0)
	{
		write(stream->fileno, stream->outbuffer, stream->size);
		fsync(stream->fileno);//刷新内核级缓冲区
		stream->size = 0;
	}
}


int mfwrite(const void* ptr, int num, mFILE* stream)
{
	memcpy(stream->outbuffer + stream->size, ptr, num);
	stream->size += num;
	if(stream->flag == FLUSH_LINE && stream->size!=0 && stream->outbuffer[stream->size - 1] == '\n')
	{
		mfflush(stream);
	}
	return num;
}



void mfclose(mFILE* stream)
{
	if(stream->size > 0)
	{
		mfflush(stream);
	}
	close(stream->fileno);	
	free(stream);
	
}

